1. Field of the Invention
The present invention relates to a semiconductor device, and in particular, to a lateral diffused metal-oxide-semiconductor transistor (LDMOS) integrated with a silicon controlled rectifier (SCR).
2. Description of the Related Art
Improving semiconductor device reliability has become technically challenging, due to further scaling of the semiconductor device and demand for smaller dimensions and increased functions of consumer products. Semiconductor devices, however, may suffer from electrostatic discharge (ESD) damage when fabricated, assembled, delivered, tested or applied. Thus, ESD protection technology is required for semiconductor devices to prevent against possible ESD damage and insure quality thereof. Currently, the endurance voltage of the ESD protection device is required to be higher than 8 kV. In conventional ESD protection methods, a silicon controlled rectifier (SCR) is used as the ESD protection device to improve endurance voltage and economize chip area. However, if the SCR has an overly low holding voltage, the SCR may be triggered in the normal operation voltage and the semiconductor devices may be damaged due to a latch-up phenomenon.
Thus, a novel semiconductor device having an ESD protection device with a tunable holding voltage is desired.